1. Field of the Invention
The invention relates to a vane pump for delivering pasty substances particularly sausage stuffing, e.g. for the purpose of producing portions of even weight and/or volume, comprising a casing surrounding a pump chamber and having an inlet and and an outlet and a pump rotor driven to rotate in the casing and having guided, plate-like slides, which are arranged to be guided displaceably in radial direction and to engage in sealingly sliding manner on the axial boundary surfaces of the pump chamber and which over at least part of one rotation together with the pump rotor are kept in contact with the radial inner wall of the pump chamber.
2. Prior Art
Vane pumps of this type are known in numerous different constructions from the prior art.
Reference is e.g. made to French Patent 2 205 119, in which use is made of a circular pump rotor provided with plate-like slides, which rotor is mounted so as to revolve in a cylindrical casing, and has an eccentric arrangement. During the rotation of the slides, they are on the one hand supported on the inner wall of the casing and on the other hand on a sleeve arranged within the pump rotor and positioned centrally with respect to the casing. Following onto the crescent-shaped pump chamber, the supply and discharge openings face one another between said sleeve and the inner area of the circular pump rotor.
British Patent 1 056 529 discloses a vane pump based on a different design. This apparatus used as a filling means for filling sausage stuffing into skins has a pump rotor eccentrically mounted in a casing and having the form of a driven hub, which rotor is equipped with plate-like slides radially guided therein. The slides are supported on the inner wall of the casing and are kept in contact with the inner wall in a channel curve or cam worked into an axial terminating surface thereof. Whereas, under axial orientation, the inlet port is connected to the crescent-shaped pump chamber, the outlet port is positioned tangentially.
The principle which is mainly used in practice corresponds to the latter apparatus with respect to the positioning of the inlet and outlet ports. Particularly in the case of highly viscose and low moisture content sausage stuffing types, difficulties are encountered in bringing about a complete filling of the pump chamber, so that the dosing accuracy is unsatisfactory.
3. Object of the Invention
It is the main object of the present invention to improve the degree of filling of the pump chamber.